Treatment Planning pt. 7-8

Treatment Planning pt. 7-8

• 1.
  Outline for 1/28/09Take home messages from last week Pick up implant DVD and look over the treatment planning section and single tooth implant section. Questions asked during the week Ten treatment planning cases Single tooth implants Implants with removable prosthodontics
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  Take home messageslast week: Tx. Planning with implants Understanding the incidence and reason for implant complications is important when you are treatment planning with implants. Many of the complications seen with dental implants occur because of a lack of coordination between the restorative dentist, surgeon and laboratory technician. You need to work with people you trust.
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  Take home messageslast week: Tx. Planning with implants Complications with single tooth implants occur more often in the posterior than anterior part of the arch. Screw loosening occurs more often when implants are single units than when implants are splinted together. Bruxisim is a big deal- about 20% of the population will brux at some point in their life, and bruxing can increase complications.
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  Take home messageslast week: Tx. Planning with implants You should know which complications are reversible and which are irreversible. You should understand some of the common reasons for material fracture. You should understand the basic steps in the fabrication of a surgical guide and understand what a surgical guide does for you and what it does not do for you.
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  Take home messageslast week: treatment planning with implants Understand the reversible and irreversible complications with implants.
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  Questions this weekGoodacre; clinical complications in fixed prosthodontics Fixed dental prostheses; complications caries 18%, need for endo 11%, loss of retention 7% Single crowns; complications endo 3%, porcelain fracture 3%, loss retention 2%. Why the big difference between FDP and single units- will be on test.
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  Questions this weekWhy do we use 35 N torque when tightening the screw to the implant abutment crown? Answer: You want to create pre-load in the screw to provide what is called clamping force. Pre-load basically means stretching the screw. You want to develop as much pre-load as you can without damaging the screw head. If you use more than 35 N you can damage the screw head.
• 8.
  Questions this weekWhy do we use a torque wrench to tighten abutment screws? Answer: With hand tightening you can only develop about 15 N force. Screw loosening is much more likely with 15 N tightening force than 35 N force because of less pre-load or stretching of the screw.
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  Questions this weekWhy do we have the patient back to re-tighten the implant? Answer: After you tighten the screw there is a process of “embedment” which basically is the compression of surface imperfections over time. As the surface imperfections compress, the pre-load of the screw decreases. By having the patient back you can tighten the screw again and have a higher pre-load.
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  Questions this weekWhy is it that the time necessary for implants to osseointegrate to the bone is so much shorter now (2-3 months rather than 4-6 months)? Answer: Implant surfaces have changed from milled titanium to a roughened surface (often by acid etching) that makes the surface more interlocking and bioreactive.
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  Titanium Implants –Current Surfaces Methods Histomorphometric analysis Shear strength evaluations Gene expression studies Clinical studies have implied that the rough surfaces are superior particularly the acid etched surfaces. Why are they superior? Mechanical interlocking Bioreactive
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  Titanium Implants -Surface Modification 2 nd Generation Surface roughness and the bone appositional index Initial studies indicated that the bone appositional index achieved is 50% greater with rough surfaces as compared to machined surfaces (Buser et al, 1991; Weinlander, 1993; Hamada, 1995; Nishimura and Ogawa, 2000, 2003) Dual Acid etched Electrolytically enhanceed Sandblast Acid-ethched
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  50 µm Nearzone Far zone Histomorphometry Acid etched vs Machine surface More recent studies (Ogawa and Nishimura, 2000, 2003), reconfirm these findings * * Bone-implant contact ratio 0 20 W2 W4 40 60 80 (%) Machined Acid etched
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  Summary of Ogawa’sand Nishimura’s work re: gene expression The placement of implants induces a phenotypic alteration (gene expression) of wound healing cells. The double acid etched surfaces evoked activation of additional selected bone genes , which may be associated with enhanced interfacial strength and accelerated bone formation
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  Questions this weekWhy is initial stabilization important for the wound healing of implants? Answer: If you have very much micromovement the predictability of osseointegration is compromised. Please consider the following graph from my teacher John Beumer at UCLA.
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  Micromotion Two types of micromotion: it may be tolerated , or it may be deleterious Micromotion appears to permit bone ingrowth, Macromotion appears to preclude it From Maniatopoulos C, Pilliar RM and Smith DC J Biomed.Mater Res 1986 150µm 500µm 50µm Tolerated Deleterious
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  Ten cases Iwant to go through 10 patient treatments with you to highlight and review the treatment planning principals you have learned from lecture, your reading and the DVD.
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  Favorable bone width,depth, May need crown #2 for vertical height Pt preferred chewing Splinted crowns Bicuspid size
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  Consider shortened dentalarch; depend on pt age, chief concern If 5.0 mm internal connection then ok with one implant.
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  Consider caries history,meds, compliance of pt. Pt health Function; 6 teeth better than 2 imlants,bar,clip Function; 4 implants often better than 2, especially if wide AP spread
• 21.
  From a functionalstandpoint, two implants will probably not provide as high a level of function as 6 teeth but 4 implants will allow higher function than anterior teeth and extension partial denture.
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  Extract 1,2,31 Implant#29, consider #19 Upper partial
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  Space measures 14mm. How many implants? Would be 2 implants, perhaps adjusting occlusal plane first.
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  Carefully review historyIs the patient at high risk for caries? Will attempts to save the tooth compromise a future implant site? If you did crown lengthening would you later have the vertical height for implants?? Because opposing a partial denture can use 3 implants to replace 4 teeth .
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  Check space toIA nerve Check to make sure more than 5 mm to opposing arch How does the ridge look?--- narrow How long after extraction of 27,28 would you wait for implant placement?
• 26.
  Part of a4 unit FDP Decay on distal Sinus is high Extract #3 and use three splinted implants Not a new FDP because of high caries risk.
• 27.
  Treatment planning decisionsfor single tooth implants Do I take out or try to restore the tooth? Do I complete a FPD or implant or RDP? Do I need site preparation? Immediate placement or delayed? Do I use a narrow diameter or wide diameter implant? Do I use an internal connection or external connection implant? Platform switching? Do I splint the implants? Do I cement or use screw retained?
• 28.
  Evaluate how muchcrown lengthening would be necessary if you were to save the tooth. Determine from the patient history and clinical examination how many implants make sense. If the patient has high biting forces you would need two splinted implants. If the patient is older and has sufficient tooth-to-tooth stops you might consider a SDA. If the patient has low levels of implant loading and a wide arch, you might consider a single wide diameter implant.
• 29.
  Patient presented withdeep caries on the mesial of the first molar. Even though RCT is possible, other problems like root proximity are seen. Here I would probably proceed with RCT, a build-up and a crown.
• 30.
  Be sure tocheck the anatomic limitations before you promise options to a patient. In this situation, make sure you have the vertical space above the IA In this example you have adequate tooth stops so SDA would be an option as would a FDP but a single tooth implant would most likely be the best option.
• 31.
  In this caseyou have adequate ridge height and width for a wide diameter implant that is more than 10 mm long; so, ask for a 5.0mm diameter implant. Remember in the posterior a wider diameter is better.
• 32.
  In general, youwould not complete high risk procedures like root amputations. Normally, you would complete a single tooth implant if necessary. Why do you think a root amputation was completed here??
• 33.
  If you didcrown lengthening you would compromise an implant site. You probably would not want a FDP because of the caries activity you see on the mesial of the second molar. A single tooth implant is the logical option. However, what does that large facet on the mesial of #31 tell you??
• 34.
  Treatment planning decisionsfor single tooth implants Do I take out or try to restore the tooth? Do I complete a FPD, implant or RDP? Do I need site preparation? Immediate placement or delayed? Do I use a narrow diameter or wide diameter implant? Do I use an internal connection or external connection implant? Platform switching? Do I splint the implants? Do I cement or use screw retained?
• 35.
  FDP, RDP orimplant?? You know the comparison of an implant, FDP or RDP. The RDP is less expensive, takes less treatment time than an implant, is often less comfortable than an implant but is generally tolerated if not a distal extension. The FDP also takes less treatment time than an implant, is also less expensive than the implant, but has a higher risk of failure if the clinical crown height is not sufficient or if the patient has a high caries risk.
• 36.
  FPD Success Rates87% 10 yr success rate,69% at 15 years Failure by recurrent caries (18%),loose retainer (7%), porcelain fracture 6.1%, Endo 5%, Perio 4%. Please read Goodacre et al. and Curtis
• 37.
  Implant success ratesSurgical success 92% (Moy) Restorative complications; porcelain fracture (12%), screw loosening (7%), screw fractures (4%), metal frame fractures (3%). Please read Goodacre et al. and Curtis
• 38.
  Treatment planning decisionsfor single tooth implants Do I take out or try to restore the tooth? Do I complete a FPD, implant or RDP? Do I need site preparation? Immediate placement or delayed? Do I use a narrow diameter or wide diameter implant? Do I use an internal connection or external connection implant? Platform switching? Do I splint the implants? Do I cement or use screw retained?
• 39.
  Determine what thepatient’s expectations from treatment are Determine where bone might be grafted from. Then move foreword knowing that much more force will be on the implants because of the lower natural dentition.
• 40.
  1)Complete diagnostic set-up2)Index teeth 3)Place pins where you want implants 4) Complete 0.060 suck-down
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• 42.
  If you dofixed, then you need to break it into segments; trying to have the prosthesis retrievable. Often lip support is less than ideal with a implant supported fixed prosthesis.
• 43.
  Site preparation forimplants Orthodontics Ridge splitting Onlay grafting Membranes
• 44.
  Be sure toget the height of the implants correct; images of CT, pano
• 45.
  In contrast tothe patient case presented this patient did not have any site preparation.
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• 47.
  A connective tissuegraft was added to hide the margin of the angulated implant.
• 48.
  Treatment planning decisionsfor single tooth implants Do I take out or try to restore the tooth? Do I complete a FPD, implant or RDP? Do I need site preparation? Immediate placement or delayed? Do I use a narrow diameter or wide diameter implant? Do I use an internal connection or external connection implant? Platform switching? Do I splint the implants? Do I cement or use screw retained?
• 49.
  Dental Implants
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  Nevin, M JPerio,2005 Use open tray, have pre-selected denture tooth, use screw retained, out of occlusion, don’t touch for several months, altering proximal contacts to work papilla .
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• 58.
  Immediate or EarlyLoading Was it feasible with the original machined surface? Blood clot formation Angiogenesis Osteoprogenitor cell migration Woven bone formation Deposition of lamellar bone Secondary remodeling of the woven bone Biologic processes to complete osseointegration* * In humans these events take about 4-5 months with machined surfaces In most cases no!!! WHY?
• 59.
  Initial Primary Stability( 1 st few days) Function of Local bone quantity and quality Implant geometry Surgical procedure (skill) Two main factors: 1. Amount of initial bone contact 2. Lateral compression of the osteotomy creating local compression stresses (hoop stresses) Courtesy Dr. C. Stanford
• 60.
  Treatment planning decisionsfor single tooth implants Do I take out or try to restore the tooth? Do I complete a FPD, implant or RDP? Do I need site preparation? Immediate placement or delayed? Do I use a narrow diameter or wide diameter implant? Do I use an internal connection or external connection implant? Platform switching? Do I splint the implants? Do I cement or use screw retained?
• 61.
  Surface Area ofImplants Diameter 3.75 4mm 5mm 6mm 2 x 3.75 mm Surface Area Baseline +8% +35% +61% +100%
• 62.
  What diameter doI use? Keep 1.5 mm from adjacent teeth. Keep 2.0 mm from adjacent implant Error on side of narrow in anterior and wide in posterior 5.0 3.5
• 63.
  Treatment planning decisionsfor single tooth implants Do I take out or try to restore the tooth? Do I need site preparation? Do I complete a FPD, RDP or implant? Do I use a narrow diameter or wide diameter implant? Do I use an internal connection or external connection implant? Platform switching? Do I splint the implants? Do I cement or use screw retained?
• 64.
  Internal vs. Externalconnection Generally use internal connection Can splint divergent implants up to 40 degrees with both internal/external Screw loosening is related more to pre-load than connection type
• 65.
  Treatment planning decisionsfor single tooth implants Do I take out or try to restore the tooth? Do I need site preparation? Do I complete a FPD, RDP or implant? Do I use a narrow diameter or wide diameter implant? Do I use an internal connection or external connection implant? Platform switching? Do I splint the implants? Do I cement or use screw retained?
• 66.
  To splint ornot to splint?
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• 68.
  Splinting of implantsAssess forces Patient factors; wt, gender, skeletal form, bone volume, quality Dental factors; proximal teeth, opposing teeth, location in arch Implant factors; wide or narrow implant
• 69.
  Splinting of implantsTo protect integrity of prosthesis; less screw loosening or breakage For biomechanical reasons to distribute forces to wider area of bone Splinting somewhat less comfortable for patients
• 70.
  Splint if boneis grafted, or low density
• 71.
  Internal vs. Externalconnection Platform surface area is very similar
• 72.
  Platform switching 4.8mm 4.1 mm
• 73.
  Platform switching Creatinghorizontal offset In theory, less bone loss When have to use short implants 4.8 mm 4.1 mm
• 74.
  Platform switching Traditionally,you see bone loss to the first or second thread. Micrograp; establishing biologic width Platform switching is an attempt to minimize the bone loss
• 75.
  Treatment planning decisionsfor single tooth implants Do I take out or try to restore the tooth? Do I need site preparation? Do I complete a FPD, RDP or implant? Do I use a narrow diameter or wide diameter implant? Do I use an internal connection or external connection implant? Platform switching? Do I splint the implants? Do I cement or use screw retained?
• 76.
  Cement or screwretained More complications with screw retained More retrievable with screw retained
• 77.
  Cement or screwretained When tissue is thick consider screw retained Need to be very careful to remove all cement if use cement retained Remember soft tissue connection is not the same between teeth and implants!!!!!!!!
• 78.
  Cement or screwretained When use cement on restoration do not have it very far sub-gingival Consider all ceramic abutments
• 79.
  Cement or screwretained When use cement on restoration do not have it very far sub-gingival Consider all ceramic abutments
• 80.
  Don’t always tryto be first Treat every patient as if they were a family member
• 81.
  Fibers connect softtissue with bone and cementum Fibers only circumferential to implant Tooth Fibers run perpendicular, vertical and circumferential to tooth Implant Fibers do not insert into implant
• 82.
  Cement or screwretained Use cemented when screw access hole is close to facial to avoid porcelain fracture
• 83.
  Cement or screwretained Use screw retained with all removable bars Use screw retained on cantilevers because higher risk
• 84.
  Other considerations forsingle tooth implants Place implant platform 2-3 mm below adjacent tooth CEJ. Remember at least 1.5 mm from proximal teeth
• 85.
  Other considerations forsingle tooth implants Often use narrower diameter implant so have at least 1.5 mm proximally to adjacent tooth.
• 86.
  Other considerations forsingle tooth implants Seldom will you use an implant diameter greater than standard diameter in the maxillary anterior An exception is sometimes the maxillary canine
• 87.
  Other considerations forsingle tooth implants In maxillary anterior ask for placement that would allow screw retained; better esthetics, easier provisional, retrievable
• 88.
  Other considerations forsingle tooth implants If placed too far to the palatal will introduce cantilever (A/P) and result in more difficult esthetics because of ridge-lap.
• 89.
  Other considerations forsingle tooth implants In maxillary anterior if you have to restore an implant that is facial to the incisal edge you will need a cement on restoration
• 90.
  Other considerations forsingle tooth implants Be careful with occlusion On implant crowns have very light occlusion when the patient closes hard Avoid lateral forces on implants
• 91.
  Please list themistakes you can see with this implant placement
• 92.
  Patient worries aboutesthetics; you need to also worry about function
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  Steps for asingle tooth implant
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  Tell me thesteps
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  What is wrong?
• 97.
  Site preparation maynot be necessary if the patient’s smile line is not very high. My preference is screw retained, using a metal lingual for less bulk and improved contours.